Citation

Dahir SH, Henry JJ. Transp. Res. Rec. 1979; 715: 69-76.

Copyright

(Copyright © 1979, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Preliminary results of a three-year program to investigate possible causes of seasonal and short-term variations in skid resistance are presented. The program was initiated in 1976 at the Pennsylvania State University to develop a method for predicting the lowest skid number a pavement is expected to attain during the year from a skid-resistance measurement made at any time during the year.

RESULTS of two years of testing indicate that skid-resistance variations of 15-30 SN sub 40 occur at the changes of season from early to late fall and early to late spring. Higher numbers occur in the winter season. Skid numbers vary by about 25 percent between rainfall periods whether or not the surface is subject to significant traffic. Higher skid numbers are observed after heavy rainfall. Where traffic is low (average daily traffic is less than 1000), only minor macrotexture changes are noted from one seson to another. On these pavements, therefore, microtexture changes are expected to cause the variations in skid resistance. Bitumionous surfaces containing sandstane gravel aggregate are subject to small variations in skid resistance over time, whereas surfaces containing limestone and dolomite are subject to large variations. Temperature has been found to and dolomite are subject to large variations. Temperature have insignificant effects on skid resistance.